While the U.S. failure to secure the Mexican border is a perpetual headliner, serious national security issues also prevail along the northern border and some of the alarming details are featured in a new government report that’s been redacted to avoid disclosing sensitive information.

It says that the U.S. Border Patrol isn’t adequately guarding a rural and dangerous stretch of the Canadian border that runs from Washington to Montana and is rife with drug smuggling and potential terrorism and gang threats. The area is considered an important entry point for aircraft that smuggle drugs from Canada, according to the findings of the Government Accountability Office (GAO), the investigative arm of Congress.

A Montana senator requested the probe to assess drug trafficking and terrorist threats along the mostly unmanned, 1,000-mile stretch of federal land adjacent to Canada. The entire northern border is around 4,000 miles, but the quarter that is federal and tribal land is especially difficult to patrol because the remote and rugged terrain limits law enforcement presence.

The investigation also includes the 800 miles of federal and tribal land situated along the Mexican border, which is equally vulnerable to illegal cross-border activity. Much has been written about that over the years, however, and the media in Arizona and Texas regularly covers the crisis while the north is largely ignored.

Because the terrain is inaccessible and Border Patrol resources are limited, the scope of criminal activity is mostly unknown, according to the GAO findings. The Homeland Security agency responsible for protecting the border simply doesn’t have the manpower or tools to do its job in treacherous terrain spanning from Washington to Montana.

The problem is biggest in the Border Patrol’s Spokane sector, which is a prime entry point for high-potency marijuana from Canada. The sector covers five national forests, two wilderness areas and a national park. Border Patrol officials admit that the level of illegal activity is significantly higher than what’s reflected in the number of drug seizures and apprehensions, which has actually decreased in the last few years.

Smuggling of drugs and other contraband in the area is substantial, according to Border Patrol assessments included in the report, though actual figures may never be known. The agency also admits there are risks related to terrorism and gangs yet most of the sector is a low-level monitored area that remains vulnerable to exploitation.